Managing two languages relates to managing two goals: fMRI evidence from task-switching

Kelly A. Vaughn1, Arturo E. Hernandez1; 1University of Houston

Whether bilingualism is related to cognitive control in non-verbal tasks is a topic of debate among researchers (e.g., Paap, 2016). The current study used fMRI to compare brain activity in Spanish-English bilingual and English monolingual young adults during a shape-color switching task, in which each non-verbal switch or repeat cue was followed by 8-12 trials, and then another cue. The goal of the study was to understand whether task performance or fMRI activity was related to bilingual status. Bilinguals responded significantly more slowly and accurately than monolinguals across all trials. fMRI activity was analyzed at an FWE-corrected alpha of 0.05 for the switch > repeat and repeat > switch contrasts for the cues and for the trials. Monolinguals had the most significant fMRI activity in cognitive control regions (i.e., frontal cortex, anterior cingulate cortex, inferior parietal lobule, and basal ganglia) for the switch > repeat cues contrast, with additional significant activity in these regions during the trials. Bilinguals showed less significant fMRI activity than monolinguals for each task comparison. Overall, these findings lead to the conclusion that bilinguals handle a non-verbal switching task by monitoring conflict throughout the task and controlling speed to improve accuracy, whereas monolinguals handle the same task by responding to each cue as it comes and sacrificing accuracy for speed. This study suggests that bilingual experience, which may involve frequent monitoring of two languages, relates to successfully monitoring two task goals; monolingual language use, conversely, relates to a focus on one task goal at a time.